Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Question about replacement transformer for 37-660
#1

I have am looking for a replacement for the output transformer for this radio. I have a line matching transformer with 5 primaries: 500 ohm,1k,2k,4k,and 8k. Output is 4ohm or 8ohm, listed as 10 watts.
Radio schematic calls for 370 ohm and 330 ohm ct primary on transformer (has two 6f6's)
Will this work on this radio? If not, any suggestions on what will work for a replacement?
Thanks,
Bill
#2

Just remember that those "300 ohm" DC resistance numbers on schematics have nothing to do with audio impedance values. You can forget those DC numbers for this exercise.

You should be up in the 'several K' numbers for impedance on the primary. I'd go with the 4k/8k options. It will vary if you feed a 4 vs an 8 ohm speaker. An original Philco speaker of that era will be closer to 4 rather than 8 ohms. I think they lean towards the ~ 2.6 ohms neighbourhood .

The AF xfmr behaves as a 'ratio' animal to match the tubes to the speaker at AUDIO frequencies. Just try it and see. Dunno your specific transformer but you should be able to come close to spec. Lots of leeway.

-Bill
#3

Thank you for your help. I will try it at 4k.8k primary, l don't understand the impedance vs resistance on these transformers. It does have an original philco speaker, but not from this radio. Is the 330/370 ohm value in the schematic significant as far as the load on the audio tubes?
Thanks,
Bill
#4

Hi,
No, those resistances are simply noted as a troubleshooting aid so that a repairman would know what to anticipate while troubleshooting with an ohmmeter.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
12' Philco
If it is 12', either Kareem or Andre would have to jump pretty high to look at the front panel. Kareem would have an e...morzh — 01:48 PM
12' Philco
And here's a story about the tires on the truck. Same "no-stoop" guy must have installed these! Take care a...GarySP — 01:17 PM
Hickok AC51 tube tester
I think they have only shown the secondaries of the transformer. Two of them feed the rectifiers' filaments.morzh — 12:58 PM
IF can wire size and Rubber mounts?
Arran If the wire inside cans is the gauges you mentioned, the sole reason for that would be mechanical, to stiffen t...morzh — 12:56 PM
12' Philco
Rod, Yes, I know, but the Giant Philco is not around anymore either, so I go by whoever was alive fairly recently. H...morzh — 12:54 PM
Hickok AC51 tube tester
Absolutely no one is going to reverse engineer that circuit. Even the iron core is missing.RodB — 10:37 AM
IF can wire size and Rubber mounts?
Thanks to both members for your help regarding wire and tuner mtg supports. regards--Johngeorgetownjohn — 09:33 AM
Hickok AC51 tube tester
Note that no power cord, power switch, or power transformer switch are shown. That (along with my experience with full s...DaleHCook — 07:09 AM
IF can wire size and Rubber mounts?
A pair of wire strippers can give you an idea of what the existing gauge of the wire leads are in the IF can, I think it...Arran — 06:07 AM
My last cabinet for this year
Hello Dan, That is really beautiful what great looking radio you have ! I have friends who live in Calgary and the wea...radiorich — 01:51 AM

[-]
Who's Online
There are currently 5583 online users. [Complete List]
» 2 Member(s) | 5581 Guest(s)
AvatarAvatar

>